There have been many recent suggestions that a specification shouldn't be written like a recipe for cherry pie. Rather, it should state the desired end product and leave the responsibility for the means of accomplishment to the contractor, relying on testing to insure compliance. This approach has much merit. For one thing, a competent contractor has no need of advise on how to do his work and for another, competition and the exercise of ingenuity are encouraged by permitting a maximum degree of freedom. This is reflected in lower bid prices and means a savings to the owner. One of the major problems is that of determining if the concrete actually possesses the required characteristics. Of course rely heavily on cylinder test and while it is true that many of the desirable properties of concrete bear a relationship to the compressive strength, there are many other properties which do not such as shrinkage. Another major problem is the seriousness of non-compliance. Even if it were possible to precisely defining the required characteristics, and even if compliance could be determined by means of simple tests, engineers could not entirely divorce themselves from a responsibility to forestall major difficulties as much as possible. So it would appear that the ideal approach must be somewhat modified; first to assure that the required properties will be obtained; and second to insure that there is at least a reasonable expectation of compliance. In effect this means that in addition to specifying results such as strength, slump, or tolerances, which will be measured or tested, requirements regulating the types and quality of materials to be used must be added and acceptable procedures for mixing, placing and curing must be specified.